Making quantitative biomicrofluidics from microbore tubing and 3D-printed adapters

Microfluidic technology has tremendously facilitated the development of in vitro cell cultures and studies. Conventionally, microfluidic devices are fabricated with extensive facilities by well-trained researchers, which hinder the widespread adoption of the technology for broader applications. Enlightened by the fact that low-cost microbore tubing is a natural microfluidic channel, we developed a series of adaptors in a toolkit that can twine, connect, organize, and configure the tubing to produce functional microfluidic units. Three subsets of the toolkit were thoroughly developed: the tubing and scoring tools, the flow adaptors, and the 3D cell culture suite. To demonstrate the usefulness and versatility of the toolkit, we assembled a microfluidic device and successfully applied it for 3D macrophage cultures, flow-based stimulation, and automated near real-time quantitation with new knowledge generated. Overall, we present a new technology that allows simple, fast, and robust assembly of customizable and scalable microfluidic devices with minimal facilities, which is broadly applicable to research that needs or could be enhanced by microfluidics.     

环境科学专业开设微流控分析技术课程的必要性与可行性

微流控分析技术已成为生物、化学、流体物理学等多学科的基本研究手段,并有力地促进了这些学科的发展。近年来,国际上将该分析技术应用于环境分析监测领域已成为一种趋势。本文探讨了在这种形势下为环境科学专业学生开设微流控分析课程的必要性、可行性,并对如何将该课程导入环境分析课程板块给出了一些具体的设想。     

语言研究与现代科学视野

长久以来,关于语言的产生和语言的本质,一直都是语言研究者们所关注和探索的问题。本文从历史发展的角度简述了人类对自身语言认识的不断发展。在早期的人类语言研究中,语言起源充满神秘色彩,语言只是研究其他人类精神财富的一种文字工具,还不能称之为真正的语言研究;到了近代,尤其是现代,新的科学技术使得人类对语言的研究产生了质的飞跃,语言研究趋于本体化。语言研究者们对人类大脑的语言机制、语言的起源以及语言习得等方面展开了大量的研究和实验,语言研究的理论和方法更为科学和理性,研究内容趋于语言本体,研究领域更具融合性,朝着认识人类自身的目标积极努力着。     

Influence of human behavior and the principle of least effort on library and information science research

This study identified the influence of the main concepts contained in Zipf's classic 1949 book entitled Human Behavior and the Principle of Least Effort (HBPLE) on library and information science (LIS) research. The study analyzed LIS articles published between 1949 and 2013 that cited HBPLE. The results showed that HBPLE has a growing influence on LIS research. Of the 17 cited concepts that were identified, the concept of “Zipf's law” was cited most (64.8%), followed by “the principle of least effort” (24.5%). Although the concept of “the principle of least effort,” the focus of HBPLE, was not most frequently observed, an increasing trend was evident regarding the influence of this concept. The concept of “the principle of least effort” has been cited mainly by researchers of information behavior and served to support the citing authors’ claims. By contrast, the concept of “Zipf's law” received the most attention from bibliometrics research and was used mainly for comparisons with other informetrics laws or research results.     

Automatic sequential fluid handling with multilayer microfluidic sample isolated pumping

To sequentially handle fluids is of great significance in quantitative biology, analytical chemistry, and bioassays. However, the technological options are limited when building such microfluidic sequential processing systems, and one of the encountered challenges is the need for reliable, efficient, and mass-production available microfluidic pumping methods. Herein, we present a bubble-free and pumping-control unified liquid handling method that is compatible with large-scale manufacture, termed multilayer microfluidic sample isolated pumping (mμSIP). The core part of the mμSIP is the selective permeable membrane that isolates the fluidic layer from the pneumatic layer. The air diffusion from the fluidic channel network into the degassing pneumatic channel network leads to fluidic channel pressure variation, which further results in consistent bubble-free liquid pumping into the channels and the dead-end chambers. We characterize the mμSIP by comparing the fluidic actuation processes with different parameters and a flow rate range of 0.013 μl/s to 0.097 μl/s is observed in the experiments. As the proof of concept, we demonstrate an automatic sequential fluid handling system aiming at digital assays and immunoassays, which further proves the unified pumping-control and suggests that the mμSIP is suitable for functional microfluidic assays with minimal operations. We believe that the mμSIP technology and demonstrated automatic sequential fluid handling system would enrich the microfluidic toolbox and benefit further inventions.     

我国科技金融发展效率的影响因素研究 —基于模糊集的定性比较分析

基于2011—2018年我国30个省（区、市）的面板数据，运用DEA-BCC模型测算出我国科技金融发展效率，并运用模糊集定性比较分析法探讨了科技金融政策、金融发展程度、科研经费强度、政府科技支持力度、科研人数和科研人员学历等因素对我国科技金融发展效率的协同效应。研究表明：（1）高效的科技金融发展具有“多重并发”的特点，受多个因素共同作用，其中科技金融政策是促进科技金融发展的重要因素；（2）推动地区实现高效科技金融发展的路径有四条，分别为政策平衡型、全面协作型、科研投入型和环境人力型。     

Microfluidic devices for cell cultivation and proliferation

Microfluidic technology provides precise, controlled-environment, cost-effective, compact, integrated, and high-throughput microsystems that are promising substitutes for conventional biological laboratory methods. In recent years, microfluidic cell culture devices have been used for applications such as tissue engineering, diagnostics, drug screening, immunology, cancer studies, stem cell proliferation and differentiation, and neurite guidance. Microfluidic technology allows dynamic cell culture in microperfusion systems to deliver continuous nutrient supplies for long term cell culture. It offers many opportunities to mimic the cell-cell and cell-extracellular matrix interactions of tissues by creating gradient concentrations of biochemical signals such as growth factors, chemokines, and hormones. Other applications of cell cultivation in microfluidic systems include high resolution cell patterning on a modified substrate with adhesive patterns and the reconstruction of complicated tissue architectures. In this review, recent advances in microfluidic platforms for cell culturing and proliferation, for both simple monolayer (2D) cell seeding processes and 3D configurations as accurate models of in vivo conditions, are examined.     

深海极端环境原位探测技术研究现状与对策

深海极端环境塑造了特殊的生命过程,资源潜力巨大,对其探测与研究是国际地球科学前沿,但深海严苛的高压环境极大地限制了深海采样及探测技术的应用。深海原位探测技术可以在不改变被测物位置及状态的条件下,获取深海样品的组分及含量信息,因此被越来越广泛地应用到深海极端环境的研究工作中。深海极端环境原位探测技术拥有广阔的前景,但作为一种新兴的探测技术仍需解决诸多科学难题。文章总结了国际和国内深海极端环境原位探测技术的研究进展,在分析当前我国深海极端环境研究现状基础上,提出未来我国深海极端环境原位探测技术发展对策。     

Simulation and experimental determination of the online separation of blood components with the help of microfluidic cascading spirals

Microfluidic spirals were used to successfully separate rare solid components from unpretreated human whole blood samples. The measured separation ratio of the spirals is the factor by which the concentration of the rare component is increased due to the Dean effect present in a flow profile in a curved duct. Different rates of dilution of the blood samples with a phosphate-buffered solution were investigated. The diameters of the spherical particles to separate ranged from 2 μm to 18 μm. It was found that diluting the blood to 20% is optimal leading to a separation ratio up to 1.97. Using two spirals continuously placed in a row led to an increase in separation efficacy in samples consisting of phosphate-buffered solution only from 1.86 to 3.79. Numerical investigations were carried out to display the flow profiles of Newtonian water samples and the shear-thinning blood samples in the cross-section of the experimentally handled channels. A macroscopic difference in velocity between the two rheologically different fluids could not be found. The macroscopic Dean flow is equally present and useful to help particles migrate to certain equilibrium positions in blood as well as lower viscous Newtonian fluids. The investigations highlight the potential for using highly concentrated, very heterogeneous, and non-Newtonian fluidic systems in known microsystems for screening applications.     

Label-free viscosity measurement of complex fluids using reversal flow switching manipulation in a microfluidic channel

The accurate viscosity measurement of complex fluids is essential for characterizing fluidic behaviors in blood vessels and in microfluidic channels of lab-on-a-chip devices. A microfluidic platform that accurately identifies biophysical properties of blood can be used as a promising tool for the early detections of cardiovascular and microcirculation diseases. In this study, a flow-switching phenomenon depending on hydrodynamic balancing in a microfluidic channel was adopted to conduct viscosity measurement of complex fluids with label-free operation. A microfluidic device for demonstrating this proposed method was designed to have two inlets for supplying the test and reference fluids, two side channels in parallel, and a junction channel connected to the midpoint of the two side channels. According to this proposed method, viscosities of various fluids with different phases (aqueous, oil, and blood) in relation to that of reference fluid were accurately determined by measuring the switching flow-rate ratio between the test and reference fluids, when a reverse flow of the test or reference fluid occurs in the junction channel. An analytical viscosity formula was derived to measure the viscosity of a test fluid in relation to that of the corresponding reference fluid using a discrete circuit model for the microfluidic device. The experimental analysis for evaluating the effects of various parameters on the performance of the proposed method revealed that the fluidic resistance ratio (R_JL/R_L, fluidic resistance in the junction channel (R_JL) to fluidic resistance in the side channel (R_L)) strongly affects the measurement accuracy. The microfluidic device with smaller R_JL/R_L values is helpful to measure accurately the viscosity of the test fluid. The proposed method accurately measured the viscosities of various fluids, including single-phase (Glycerin and plasma) and oil-water phase (oil vs. deionized water) fluids, compared with conventional methods. The proposed method was also successfully applied to measure viscosities of blood with varying hematocrits, chemically fixed RBC_S, and channel sizes. Based on these experimental results, the proposed method can be effectively used to measure the viscosities of various fluids easily, without any fluorescent labeling and tedious calibration procedures.     

我国科技金融发展效率的影响因素——基于模糊集的定性比较分析

基于2011-2018年我国30个省份面板数据,运用DEA-BCC模型测算出我国科技金融发展效率,并采用模糊集定性比较分析法探讨科技金融政策、金融发展程度、科研经费强度、政府科技支持力度、科研人数和科研人员学历等因素对我国科技金融发展效率的组合效应。研究表明:(1)高效的科技金融发展具有“多重并发”的特点,受多个因素共同作用,其中科技金融政策是促进科技金融发展的重要因素;(2)推动地区实现高效科技金融发展的路径有4条,分别为政策平衡型、全面协作型、科研投入型和环境人力型,其中科技金融政策是促进科技与金融结合的重要因素。建议科技金融发展效率高的省份在保持自身优势的同时积极弥补不足的方面,而发展效率较低的省份应根据地区发展优势因地施策,寻找符合自身科技金融高效发展的路径。     

A microfluidic device to apply shear stresses to polarizing ciliated airway epithelium using air flow

Organization of airway epithelium determines ciliary beat direction and coordination for proper mucociliary clearance. Fluidic shear stresses have the potential to influence ciliary organization. Here, an in vitro fluidic flow system was developed for inducing long-term airflow shear stresses on airway epithelium with a view to influencing epithelial organization. Our system consists of a fluidic device for cell culture, integrated into a humidified airflow circuit. The fluidic device has a modular design and is made from a combination of polystyrene and adhesive components incorporated into a 6-well filter membrane insert. We demonstrate the system operates within physiologically relevant shear and pressure ranges and estimate the shear stress exerted on the epithelial cell layer as a result of air flow using a computational model. For both the bronchial epithelial cell line BEAS2B and primary human tracheal airway epithelial cells, we demonstrate that cells remain viable within the device when exposed to airflow for 24 h and that normal differentiation and cilia formation occurs. Furthermore, we demonstrate the utility of our device for exploring the impact of exposing cells to airflow: our tool enables quantification of cytoskeletal organization, and is compatible with in situ bead assays to assess the orientation of cilia beating.     

Smart cities: Advances in research—An information systems perspective

Smart cities employ information and communication technologies to improve: the quality of life for its citizens, the local economy, transport, traffic management, environment, and interaction with government. Due to the relevance of smart cities (also referred using other related terms such as Digital City, Information City, Intelligent City, Knowledge-based City, Ubiquitous City, Wired City) to various stakeholders and the benefits and challenges associated with its implementation, the concept of smart cities has attracted significant attention from researchers within multiple fields, including information systems. This study provides a valuable synthesis of the relevant literature by analysing and discussing the key findings from existing research on issues related to smart cities from an Information Systems perspective. The research analysed and discussed in this study focuses on number of aspects of smart cities: smart mobility, smart living, smart environment, smart citizens, smart government, and smart architecture as well as related technologies and concepts. The discussion also focusses on the alignment of smart cities with the UN sustainable development goals. This comprehensive review offers critical insight to the key underlying research themes within smart cities, highlighting the limitations of current developments and potential future directions.     

Content-oriented or persona-oriented? A text analytics of endorsement strategies on public willingness to participate in citizen science

This paper applies text analytics to study how the orientation of an endorsement strategy affects the public's willingness to participate in citizen science projects. Using 850 citizen science projects with 1,243 endorsements from an online citizen science platform Experiment.com as corpus, the orientation of the endorsement strategies is detected using the naïve Bayesian inference model with a Laplace estimator. Our results inform that 39% of the endorsements are persona-oriented while 61% are content-oriented. A persona-oriented endorsement strategy draws more participants but reduces the per capita invested. A content-oriented endorsement strategy has the opposite effect. Further, the project initiator's identity strengthens or weakens the effect of the endorsement orientation strategy. In the number of participants model, the projects initiated by the professional scientists and research students are positively moderated by persona-orientation endorsements, whereas the projects initiated by the amateur researchers are negatively moderated. The converse holds for the per capita invested model.     

Acceptance of public cloud storage services in South Korea: A multi-group analysis

As cloud computing has spread from the enterprise sector to individuals, there has been a growing need for research on the adoption of cloud computing at the individual level. However, relatively little research has investigated the differences and similarities between users and nonusers regarding the individual-level technology acceptance. To fill this gap, this study explored the differences and similarities between users and nonusers in the context of public cloud storage services of South Korea. Data (users = 210; nonusers = 187) were analyzed using structural equation modeling. For social influence, there was a significant difference between users and nonusers. For users, social influence was not a determinant for positive intention to use PCSS, whereas it was a determinant for nonusers. For other factors, there were no significant differences between the two groups, but each showed meaningful similarities: habit was the strongest predictor of the intention to use for both users and nonusers, whereas hedonic motivation was not an important concern for both; performance expectancy was a determinant for positive intention to use PCSS for both groups. Effort expectancy was a determinant for positive intention to use PCSS for users, whereas it was not a determinant for nonusers. These results can provide academic researchers and businesses with insights into individual-level adoption of cloud computing.     

“脑功能联结图谱与类脑智能研究”先导专项研究进展和展望

对大脑的认知是人类认识自然和自身的终极挑战,脑科学研究的核心是理解脑功能的结构及物质基础。中科院在2012年启动了战略性先导科技专项(B类)"脑功能联结图谱计划"(Mapping Brain Functional Connections;简称:脑联接图谱;MBFC,2012—2020),目标是对特定脑功能的神经联结通路和网络结构的解析及模拟。专项代表了脑科学研究的战略制高点,对揭示脑的工作原理、推动智能科学技术进步、增进人类身心健康等方面都具有十分重要的意义。专项设立以来,在感知觉神经环路发育和功能、视觉与本能恐惧行为的神经环路机制、情绪的神经环路编码机制、成瘾和抑郁症等脑疾病机理、意识的神经基础、基因编译技术及脑疾病的非人灵长类模型、神经元分类和功能分析技术及其应用、神经环路双色钙成像方法、神经环路结构与功能研究工具开发、深度神经网络芯片研制,以及资源库与平台建设等方面取得了一系列重要的科学发现和技术研发进展。我们将进一步按照专项十年规划,开展脑认知科学、类脑人工智能技术、脑疾病早期诊断及干预3个前沿领域的科学研究,以及相关新技术研发和脑科技资源库建设,发挥中科院在脑与认知基础研究和技术研发等领域的引领作用。     

人体器官芯片

人体器官芯片是一门新兴的前沿科学技术,也是一门典型的多学科交叉汇聚技术,对人类健康和生物产业发展具有重要战略意义,吸引了来自政府、科学界和产业界的关注,被2016年达沃斯世界经济论坛列为"十大新兴技术"之一。人体器官芯片指的是一种在载玻片大小芯片上构建的器官生理微系统,包含有活体细胞、组织界面、生物流体和机械力等器官微环境关键要素。它可在体外模拟人体不同组织器官的主要结构功能特征和复杂的器官间联系,用以预测人体对药物或外界不同刺激产生的反应,在生命科学和医学研究、新药研发、个性化医疗、毒性预测和生物防御等领域具有广泛应用前景。文章概述性介绍了人体器官芯片的起源、国际发展态势和研究进展,并对其面临的挑战和未来发展趋势予以展望。     

Microfluidic chip-based synthesis of alginate microspheres for encapsulation of immortalized human cells

Cellular transplantation is a promising technology with great clinical potential in regenerative medicine and disease management. However, effective control over patient immunological response is essential. The encapsulation of cells within hydrogel microspheres is an increasingly prevalent method for the protection of cellular grafts from immune rejection. Microfluidic “chip” reactors present elegant solutions to several capsule generation issues, including the requirement for intercapsule uniformity, high reproducibility, and sterile, good manufacturing practice compliance. This study presents a novel method for the on-chip production of stable, highly monodisperse alginate microspheres and demonstrates its utility in the encapsulation of an immortalized human-derived cell line. Four populations of immortalized human embryonic kidney cells (HEK293) were encapsulated on chip within monodisperse alginate capsules. Cell viability measurements were recorded for each of the four encapsulated populations for 90 days.     

人工智能驱动的生命科学研究新范式

生物技术和信息技术的迅速发展,使生命科学进入了数据爆发的新时代,传统生命科学研究范式难以在日益增长的生物大数据中揭示生命复杂系统的本质规律。随着人工智能（AI）在生命科学研究领域持续取得颠覆性突破,AI驱动的生命科学研究新范式呼之欲出。文章通过深入剖析AI驱动的生命科学研究的典型范例,提出了生命科学研究新范式的内涵和关键要素,阐述并讨论了新范式下的生命科学研究前沿和我国面临的挑战。     

数字人文与智慧数据视角下的北京双奥社会记忆构建研究

【目的/意义】从数字人文和智慧视角出发,构建北京双奥社会记忆,契合通过体育构建美好世界愿景,助 力打造北京双奥遗产。【方法/过程】梳理了社会记忆发展脉络,分析了社会记忆构建研究现状,对社会记忆实践应 用案例和场景进行了研判,明晰了数字人文和智慧数据概念,阐释了数字人文与北京双奥社会记忆逻辑关联。【结 果/结论】将数字人文理念、智慧数据理论、先进的计算机技术引入到北京双奥社会记忆项目构建,提出构建高维时 空智慧数据服务空间、数字记忆多重证据参照体系、多维人文价值协同合作机制、数智赋能社会记忆服务体系等四 个策略。【创新/局限】形成数字人文和智慧数据同社会记忆的三维融合,拓展了北京双奥社会记忆理论体系和方法 体系,存在相关理论分析不够透彻、社会记忆构建维度不够完善的局限。